Without limiting the scope of the invention, its background is described in connection with filtration methods and compositions.
One such invention is found in U.S. Pat. No. 7,459,121, issued to Liang, et al., directed to a method for continuous fabrication of carbon nanotube networks or membrane materials. Briefly, this patent is said to teach methods and devices for the continuous production of a network of nanotubes or other nanoscale fibers. The method is also said to include making a suspension of nanoscale fibers dispersed in a liquid medium, optionally with surfactant and/or sonication, and filtering the suspension by moving a filter membrane through the suspension, such that the nanoscale fibers are deposited directly on the filter membrane as the fluid medium flows through the filter membrane, to form a continuous membrane of nanoscale fibers. The deposition of the nanoscale fibers can occur when and where the filter membrane moves into contact with a static, porous filter element or a dynamic, porous filter element. The filtering can be conducted within a magnetic field effective to align the nanoscale fibers, and/or with the aid of vacuum to pull water through the filter membrane, applied pressure to press water though the filter membrane, or a combination thereof.
Another invention is said to be taught in U.S. Pat. No. 7,071,247, issued to Fischer, directed to a reinforced filter material. Briefly, this invention is said to teach a porous mold for use in a pressure casting process, which mold is manufactured of a polymeric material forming a matrix into which a clay and a block copolymer or a graft copolymer have been incorporated, wherein the block copolymer or graft copolymer comprises one or more first structural units (A), which are compatible with the clay, and one or more second structural units (B), which are compatible with the polymeric matrix. The invention further relates to a process for producing said mold and to the use of said mold in a pressure casting process.
United States Patent Application No. 20080185341, filed by Diallo, which is directed to water treatment by dendrimer-enhanced filtration. Briefly, the application teaches compositions and methods useful for the purification of aqueous fluids using dendritic macromolecules. The process is said to involve using dendritic macromolecules (dendrimers) to bind to or chemically transform solutes, and a filtration step to produce fluid from which solutes have been removed or chemically transformed. Examples of dendrimers that may be used in the process include cation-binding dendrimers, anion-binding dendrimers, organic compound-binding dendrimers, redox-active dendrimers, biological compound-binding dendrimers, catalytic dendrimers, biocidal dendrimers, viral-binding dendrimers, multi-functional dendrimers, and combinations thereof. The process is said to be readily scalable and provides many options for customization.
WO 2014/027197A1 filed by Nair discloses uses of graphene oxide for vapor phase separation and methods of dehydration for the separation of water using a membrane. Graphene oxide was shown to allow unimpeded permeation of water (Nair et al. Science, 2012, 335,442-444) but this work does not disclose any practical applications on this material as a membrane, (cited in paragraph [0012] in WO 2014/027197 A1).